TITLE: GCN CIRCULAR NUMBER: 28536 SUBJECT: IceCube-200929A: Upper limits from Fermi-GBM Observations DATE: 20/09/30 21:19:14 GMT FROM: Joshua Wood at MSFC/Fermi-GBM J. Wood (NASA/MSFC) reports on behalf of the Fermi-GBM team: For the IceCube high-energy neutrino candidate event IceCube-200929A (GCN 28532), at the event time Fermi-GBM was observing the reported neutrino location at: RA: 29.53 (+0.53 -0.53 deg 90% PSF containment) J2000 Dec: 3.47 (+0.71 -0.35 deg 90% PSF containment) J2000 There was no Fermi-GBM onboard trigger around the event time of the neutrino candidate. An automated, blind search for short gamma-ray bursts below the onboard triggering threshold in Fermi-GBM also identified no counterpart candidates. The GBM targeted search, the most sensitive, coherent search for GRB-like signals, was run from +/-30 s around the neutrino candidate time. From this search, no significant signal was found related to IceCube-200929A. We set upper limits on impulsive gamma-ray emission. Using the representative soft, normal, and hard GRB-like templates described in arXiv:1612.02395, we set the following 3 sigma flux upper limits over 10-1000 keV (in units of 10^-7 erg/s/cm^2): Timescale Soft Normal Hard ------------------------------------------- 0.128 s: 5.6 9.7 16. 1.024 s: 2.2 3.7 7.0 8.192 s: 0.8 1.3 2.1 These results are preliminary.